1. Field of the Invention
The field of the present invention is electronically controlled transmissions in which a roller synchro mechanism provided in the transmission is operated by a shift actuator that is electronically controlled, and steering wheel mechanisms located which deliver shifting instruction signals to the electronically controlled transmission.
2. Description of the Prior Art
There is a conventionally known electronically controlled transmission described in U.S. Pat. No. 4,817,451. Such electronically controlled transmission comprises a so-called roller synchro mechanism designed to establish a desired gear-shift stage by bringing one of a plurality of gears relatively rotatably carried on a rotary shaft into engagement with the rotary shaft through rollers. While a throttle actuator is driven to control the rotational speed of an engine on the basis of an engine rotational speed signal, transmission input and output shaft rotational speed signals and electric gear-shifting instruction signals received into an electronic control unit, the roller synchro mechanism is operated by a shift actuator, thus establishing a desired gear-shift stage.